There is increasing speculation that Washington is considering an aerial or sea missile attack on Syrian chemical weapons sites, a CNN correspondent reported on Monday.

The report quoted an anonymous senior administration official as saying, “there is intensified planning in the works.”

“As the situation in Syria becomes more grave and as we are increasingly concerned about chemical weapons use in Syria, it’s the responsibility of the US military to prepare detailed options,” the official said.

US President Barack Obama has not asked for the strike options yet, but the Pentagon is preparing all military options, the official continued. Foot troops involvement has been discussed, but a missile strike is a far likelier scenario, even though Syrian chemical stockpiles are constantly moved around the country to avoid being located.